The present invention is related to application Ser. Nos. 11/898,479 and 11/898,478, both filed on Sep. 12, 2007, herein incorporated by reference.
Prior art hold down systems, such as one disclosed in U.S. Pat. No. 6,951,078, includes an inner cylindrical member axially movable within an outer cylindrical member. A resilient member is manipulated between opposing circumferential grooves on the cylindrical members to allow the inner cylindrical member to move up to increase the axial dimension of the fastener assembly and to lock the two cylindrical members to each other when the inner cylindrical member tries to retract to its previous position. Under load conditions, the resilient member may shift out of its locking position, thus compromising the integrity of the fastener assembly.
Prior art hold down systems typically use a tie rod that extends inside a stud wall from the foundation to the top floor. Field conditions and the quality of the installation are such that the tie-rod may not be installed perpendicular to the horizontal bearing surface within the wall. In such a situation, the prior art fastener assembly may not sit squarely on the bearing surface and thus lose some bearing contact. The resulting installation may not be satisfactory since full contact between the bearing surfaces of the various components of the system is not achieved, which may compromise the holding capacity of the system.